Masted drill rig with system for applying push and/or pull force to a tool

ABSTRACT

A masted drill rig with a track longitudinally mounted on a mast with a plurality of longitudinally spaced slots. A sled with a main-section and a sub-section is mounted on the track. A double-acting hydraulic cylinder connects the main-section to the sub-section and reciprocates a pawl member with a claw foot between slot engaged and disengaged position for applying a push and/or pull force through the main-section to a tool operated by the drill rig.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a masted drill rig with a system for applying push and/or pull (crowd or extraction) force to a tool at any point along the mast through a sled operating on the mast.

Brief Description of the Prior Art

The installation of foundation systems has developed over many years and typically can be broken down to systems of two types, namely:—

1) Those systems whereby a hole is dug by means of some form of drill (rotary, vibrating or impact system) and the resulting hole is filled with a product that is used to support the load of the subsequent system or structure

2) Those systems that insert a product in to the ground (such as a helical anchor or other screw system or by vibrating or hammering a product in to the ground) whereby that product remains in the ground and is used to support the load of the subsequent system or structure

In each case the systems will use some form of tool or motive power mounted on a sled that in turn is mounted on a mast system to provide some form of guided motion.

Typically a cable winch is used to raise or lower the sled on the mast with the weight of the sled and tool and motive power providing the force to cause those items to lower on the mast

If such a mast system works mainly in a vertical orientation it is common that the only force in a vertically downward direction is that caused by the weight of the combination of sled, tool and motive power source and by the action of the tool or foundation system interacting with the ground such as an auger which may under certain conditions corkscrew in to the ground.

A drawback of this method of installation is that if the tool or foundation system encounters a hard area of ground or embedded rock or similar obstruction there is no real method to advance the tool or foundation system through the obstruction other than wait until the tool or foundation system finds its own way through

Where such a mast system is used primarily for drilling or where operation is in a non-vertical orientation the sled may be subject to an additional crowd force whereby the sled is pushed by a hydraulic cylinder, along a limited section of the mast, or pulled by a rope or chain driven mechanism.

In particular, when a hydraulic cylinder is used, the cylinder is typically attached to a fixed point on the mast at one end and to the sled at the other end. As such the distance that crowd can be applied over is limited to the stroke of the cylinder. Similarly, the area of the mast through which the crowd can be applied is limited by the position and stroke of the hydraulic cylinder. This in turn means that additional methods must be employed to establish crowd such as friction on the driven tool or kelly bar driving the tool. This increases the complexity of the equipment and reduces the effectiveness of the crowd.

In particular, when a rope or chain system is employed it is recognized that it is possible to push or pull over the extent of the mast however this presents additional issues such as the extra complexity and weight introduced by the need for a second winch to provide crowd and the weight of items such as a chain drive system that are prone to mechanical failure and other mechanical issues.

In particular, making changes to the length of a mast employing a chain driven system requires the chain to be modified in length which is time consuming and relatively costly.

The use of an additional winch in a crowd system becomes complicated and also the size of the additional feature becomes an issue when trying to manufacture smaller systems whereas the use of chain in larger systems becomes impractical due to the size and weight of chain required.

It has been recognized that a need exists for a simple method and system to affect crowd or push down on the sled of a masted system that can be applied at any point on a masted system that operates independently of the length of the mast and without the need for significant additional weight or controls or equipment.

BRIEF SUMMARY OF THE INVENTION

The present invention employs a novel approach to achieving pushing or pulling action of a sled on a masted system by encompassing the push-pull mechanism within the sled itself rather than as a mechanism fixed to the mast and the sled. A sub-section of the sled travels with the main sled during standard operating conditions and procedures.

At a time when crowd is required the sub-section of the sled is caused to lock in place on the mast. Locking can be achieved by one of several different methods including the use of brakes, the use of clamps or as in the current design, the use of a pawl or pawls that engaged in mating elements on the mast structure.

Once the sub-section of the sled is locked in place a hydraulic cylinder is actuated. One end of the cylinder is fastened to the main sled section while the alternate end is fastened to the sub-section of the sled. The actuation of the hydraulic cylinder causes the main section of the sled to push away from, or if necessary pull towards, the subsection of the sled and subsequently creates a push or a pull force as required on the main section of the sled.

The present invention, by virtue of the fact that the main sled section and sub-section of the sled run on the same support structure and by rails and by virtue of the fact that the sub-section can be caused to lock at any point of the length of the mast means that additional sections of mast can be added or removed without the need for other changes to take place, such as shortening or lengthening of a chain or cables.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

In the accompanying drawings, in which several of various possible embodiments of the invention are illustrated, corresponding reference characters refer to corresponding parts throughout the several views of the drawings in which:

FIG. 1 is an overall view of an assembly drawing of the main sled section and sub-section of the sled in normal operating condition where the main sled section and the subsection are traveling in unison.

FIG. 2 is a side projection of the main sled section and sub-section of the sled in normal operating condition where the main sled section and the subsection are travelling in unison. The locking element in this variation is a pawl and can be seen in its retracted position towards the top of the figure.

FIG. 3 is an overall view of an assembly drawing of the main sled section and sub-section of the sled. In this figure we see the main sled section and the sub-section in the crowd or extended position with the locking pawl engaged in mating elements on the mast and the hydraulic actuator (cylinder fully extended).

FIG. 4 is a perspective view of a drilling rig with a sled mounted on a track longitudinally attached to a mast. Main and sub-sections of the sled are reciprocated along the track by a double acting hydraulic cylinder for applying a pushing or pulling force on a tool.

DETAILED DESCRIPTION OF AT LEAST ONE PREFERRED EMBODIMENT OF THE INVENTION

Referring to the drawings more particularly by reference character drill rig 10 includes a mast 12 which may be vertical or angled with respect to the ground. Drill rig 10 may be fixed as shown in FIG. 4 or movable with respect to the ground. A longitudinal track 14 is mounted on mast 12. Track 14 has a T-shaped flange 16 into which a plurality of substantially identical slots 18, preferably rectangular in shape, are formed and are longitudinally spaced therealong.

Mounted on track 14 is a sled 20 consisting of a main-section 22 and a sub-section 24. Main-section 22 and sub-section 24 are adapted to slide along track 14. To this end, main-section 22 includes a pair of slide rails 26 on which is mounted a back plate 28. A support platform 30 for a power assembly 32 is cantilevered from back plate 28 with a pair of side brackets 34. A tool 36 such as a helical drill is attached to power assembly 32. Slide rails 26 extend under flange 16 with a groove 38 that grips the side edges thereof thereby securing main-section 22 to track 14 and preventing the rotation of main-section 22 around flange 16. Sub-section 24 also has a pair of slide rails 40 on which is mounted a back plate 42. Back plate 42 includes mounting blocks 44 in which is journaled a pawl 46 with a claw foot 48 about a first pivot axis 50. Slide rails 40 have a groove 52 for gripping the side edges of T-shaped flange 16 in the same manner as slide rails 26 for the same purpose.

A linear actuator such as a double acting hydraulic cylinder 54 interconnects main-section 22 and sub-section 24. A first end 56 of hydraulic cylinder 54 is rotatably attached to support platform 30 or back plate 28 of main-section 22 and a second end 58 of hydraulic cylinder 54 is attached to pawl 46 at a second pivot axis 60. First and second pivots axes 50, 60 are spaced apart such that pawl 46 provides a link for pivoting claw foot 48 between slot 18 engaging and slot disengaging positions as more particularly discussed below.

In retracted position as shown in FIGS. 1 and 2, main-section 22 and sub-section 24 are juxtaposed on track 14 with pawl 46 pivoted about first pivot axis 50 such that claw foot 48 is disengaged from slots 18. Sled 20 is thereby free to slide along track 14 under force of gravity when mast 12 is vertical or inclined towards the ground. When the gravity force provided by the weight of sled 18, power assembly 32 and tool 36 is insufficient for drilling purposes, hydraulic cylinder 54 may be energized. As hydraulic cylinder 54 extends and second end 58 rotates about second pivot axis 60, pawl 46 is rotated about first pivot axis 50 causing claw foot 48 to engage one of slots 18 as shown in FIG. 3 locking sub-section 24 to track 14 such that sub-section cannot slide. Further extension of hydraulic cylinder 54 pushes main-section 22, which is free to slide, away from sub-section 24 applying a push (crowd) force on main-section 22 which is translated through power assembly 32 to tool 36.

When double acting hydraulic cylinder 54 has reached full stroke, it may be energized to retract. As the cylinder retracts, pawl 46 is rotated freeing claw foot 48 from slot 18 and releasing sub-section 24 such that it may slide along track 14. Further retraction of hydraulic cylinder 54, pulls sub-section 24 towards main section 22 which is held in place on track 14 by tool 36. Upon reaching the starting position as shown in FIG. 1, the cycle may be repeated to produce alternate incremental movement of main-section along track 14 to advance tool 36 into the ground.

After the hole is dug or the product installed, added force may be needed to pull tool 36 out of ground and the cycle described above is reversed. As hydraulic cylinder 54 is extended, sub-section 24 is pushed away from main-section 22 on track 14. At full stroke, pawl 46 is rotated causing claw foot 48 to engage one of slots 18 fixing sub-section 24 on track 14. As hydraulic cylinder 54 retracts, main section 22 is dragged towards sub-section 24 applying a pulling or extracting force on tool 36. On the return stroke, pawl 46 releases claw foot 48 and sub-section 24 slides along track 14 towards main-section 22 while main-section 22 is held in place on track 14 by tool 36 and the cycle repeated.

In use as clearly shown in the drawings, movement of tool 36 is not limited by the position and stroke of the hydraulic cylinder 54. Nor is the system limited to a particular length of mast 12 or to the point on a masted system that additional push or pull force is needed. It will also be recognized that the previously described hydraulic operations 62 may be realized by manual remote controls or through an electronic system for the management of the digging 66. For example, operation of the double acting hydraulic cylinder 54 may be computer controlled in response to pressure sensors adapted to detect blocking of the digging equipment from insertion or extraction from the ground.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained. As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. 

What is claimed:
 1. A masted drill rig for drilling a hole or inserting a product into the ground comprising a track longitudinally mounted on a mast, said track having a T-shaped flange with a plurality of longitudinally spaced slots, a sled having a main-section and a sub-section freely slidable along the track, said main-section configured for support of a power assembly connected to a tool for drilling a hole or inserting a product into the ground, said sub-section configured for pivotable support of a pawl with a claw foot, a double acting linear actuator with a first end mounted on the main-section and a second end connected to the pawl member on the sub-section, said linear operator reciprocating the claw between slot engaged and slot disengaged position to provide alternate incremental movements of the sled along the track.
 2. The masted drill rig of claim 1 wherein the main-section comprises a pair of slide rails on which is mounted a back plate from which is cantilevered a support platform for a power assembly attached to the tool, said T-shaped flange having side edges and said slide rails having grooves for gripping the side edges of the T-shaped flange to secure the main-section to the track.
 3. The masted drill rig of claim 1 wherein the sub-section comprises a pair of slide rails on which is mounted a back plate with mounting blocks in which the pawl is journaled about a first pivot axis, said side rails having grooves for gripping the side edges of the T-shaped flange to secure the sub-section to the track.
 4. The masted drill rig of claim 3 wherein pawl has a second pivot axis spaced from the first pivot axis, said linear operator having first and second ends, said first end attached to the second pivot axis on the pawl and said second end attached to the support platform or back plate of the main-section.
 5. A masted drill rig for drilling a hole or inserting a product into the ground comprising a track longitudinally mounted on a mast, said track having a T-shaped flange with a plurality of longitudinally spaced slots, a sled having a main-section and a sub-section freely slidable along the track, said main-section configured for support of a power assembly for driving a tool, said sub-section configured for pivotable support of a pawl with a claw foot, a double acting hydraulic cylinder with a first end mounted on the main-section and a second end connected to the pawl member of the sub-section, said hydraulic cylinder reciprocating the claw foot between slot engaged and slot disengaged position to provide alternate incremental movements of the main-section or the sub-section along the track, said double acting hydraulic cylinder connected to a hydraulic circuit under manual or electronic control.
 6. The masted drill rig of claim 5 wherein the main-section comprises a pair of slide rails on which is mounted a back plate from which a support platform for the power assembly attached to the tool, said support platform cantilevered by a pair of support brackets from the back plate, said T-shaped flange having side edges and said slide rails having grooves for gripping the side edges of the T-shaped flange to secure the main-section to the track and said sub-section comprising a pair of slide rails on which is mounted a back plate on which are positioned mounting blocks in which the pawl is journaled about a first pivot axis, said slide rails having grooves for gripping the side edges of the T-shaped flange to secure the sub-section to the track.
 7. The masted drill rig of claim 6 wherein the pawl has a second pivot axis spaced from the first pivot axis, said hydraulic cylinder having first and second ends, said first end attached to the second pivot axis on the pawl and said second end rotatably attached to the support platform.
 8. The drill rig of claim 6 wherein the mast is vertically oriented.
 9. The drill rig of claim 6 wherein the mast is horizontally oriented. 